The Hardness and Corrosion Properties of Trivalent Chromium Hard Chromium

Abstract

The formulation of hard chromium plating from trivalent chromium electrolyte and its related process have been intensively studied in this work. Through optimized conditions, the coating hardness can achieve more than HV 0.1 900 without any treatment and HV 0.1 1700 after heat treatment for five minutes at 300˚C, and the thickness of hard chromium coating was about 100 µm. The hard chromium coatings show good adhesion on the carbon steel and low alloy structural steel. The corrosion resistance of hard chromium coatings was enhanced by the adding nanometer materials into trivalent chromium plating coatings. More than 120 hours salt spray corrosion resistance can be achieved with 40 to 50 microns thickness of trivalent chromium plating coatings.

Recent advances in electroless nickel‑boron coatings

“…In the presence of sulfuric acid, an equilibrium between chromic (III) and dichromic (VI) acid forms, and the dichromic acid is reduced to metallic chromium [207]. However, other technologies based on trivalent chromium are gaining popularity at the lab scale [23,[208][209][210]. The first benefit of electroless nickel plating, when compared with hard chrome, is the perfect shape and dimension compliance due to the absence of external current source and edge effects [15].…”

The Impact of Heat Treatment on the Behavior of a Hot-Dip Zinc Coating Applied to Steel During Dry Friction

“…In the case of lamellar zinc coatings, the hardness of the outer surface can reach even 500 HV, which is due to the application of thermosetting surface varnish as the last layer. Moreover, other coatings can be used as alternative solutions: heat-treated Ni–P coating (1050 HV50) [ 35 ], or even heat-treated hard Cr coating (1700 HV 0.1) [ 36 ]. As shown in the literature review, heat treatment (HT) is a method that is more and more often applied as a way of improving different coating properties.…”

Pengaruh Variasi Kuat Arus Terhadap Ketebalan, Kekerasa dan Ketahana Korosi Hasil Elektroplating Nikel-Hard Chromium Pada Baja AISI 4340

“…Hal tersebut membuktikan bahwa adanya lapisan hard chromium akan meningkatkan sifat ketahanan korosi pada material. Semakin tinggi arus, maka akan menghasilkan ketebalan lapisan yang lebih tinggi, sehingga mengakibatkan ketahanan korosi lebih tinggi [7]. Berdasarkan tren perubahan posisi kurva tersebut dapat dilihat bahwa dengan pemberian lapisan nikel-hard chromium membuat posisi kurva polarisasi anodik cendrung naik, hal itu menunjukkan bahwa jenis proteksi lapisan hard chromium merupakan jenis proteksi anodik [2].…”